Small Device Brings Big Comfort to Post-Surgical Patients

Recovery from heart and lung surgery may one day be more tolerable for hundreds of thousands of patients, thanks to a pair of surgeons and two engineering teams who developed a device that clears chest tube clogs.

The device, shown at Design & Manufacturing Midwest in Chicago this week, changes the recovery process by eliminating the need for nurses and doctors to jockey a patient's chest tube around in order to loosen clogs caused by coagulated blood and other fluids.

"With this, there's now a way to unclog the chest tube without disturbing the patient," noted Karl Sprague, project leader for Xeridiem Medical Devices, which teamed with two other companies to develop the device and its manufacturing process.

Known as the PleuraFlow Active Tube Clearance System, the device is an example of how a small idea can translate to big changes for patients. It consists of a Teflon-coated stainless steel wire inside a plastic (polyvinyl chloride) tube surrounded by a magnetized handle. The concentric handle, which slides along the outside of the tube, uses a neodymium magnet to move the magnetized stainless steel wire inside the tube. By moving the wire, which has a looped end, the handle enables nurses and doctors to break clogs and draw fluid through the tube, without adjusting the chest tube or pulling it out of the patient.

"Today, when a tube clogs, doctors and nurses will often pinch it with their fingers and try to create a vacuum to clear the clot," noted Michael Cusack, director of business development for Xeridiem Medical Devices, in an interview with Design News. "But because the tube can often be inserted deep into the patient, that can be very painful."

The PleuraFlow device, which won a Medical Design Excellence Award from UBM Canon earlier this year, eliminates the need for insertion of multiple chest tubes (often called "garden hoses") to help clear the fluids from the patients. Makers of the device claim they can clear the fluids through a single tube, which further reduces patient stress.

PleuraFlow -- initially designed by surgeons Ed Boyle and Marc Gillinov of the Cleveland Clinic -- went through several iterations before reaching the market a year ago. Boyle and his startup company, Clear Catheter Systems Inc., worked with Carbon Design Group on the design of the device and with Xeridiem on its manufacturability. As a result, the device evolved from a slitted tube with a mechanically-connected handle to an intact solid tube that employs a magnetic coupling to move the internal wire without compromising the integrity of the tube. All of the components, including the ABS (acrylonitrile butadiene styrene) handle housing, are manufacturable in volume and FDA approved.

Sprague said that the device has thus far been used on approximately a thousand patients, but plans are for it to be applicable to many of the 2.5 million thoracic surgeries than are done in the US every year. "It's something that could take off to the point where every cardio-thoracic surgery procedure could use this," Sprague said.

Cusack said the device could also see use outside of thoracic surgery, such as in nasogastric tubes, feeding tubes, and urology. "Any tube that clogs can use this technology," Cusack said.

I love these examples of small, relatively simple medical device applications that can deliver such big value and comfort to patients. Chuck, you say that the device has already been used on upwards of 1,000 patients. Does that mean it's an available offering that's cleared the requisite FDA approval process?

TJ: I don't know if they could have used a different magnetic material, but I do know that they wanted a very powerful coupling force between the magnets because they are phyically separated by the plastic tube. It takes very strong hands to pull them apart. That's why they wanted neodymium.

Yesterday's articles included one about rare earth metal shortages caused by China cutbacks. The product described in this article uses a neodymium magnet. Is its component materials sourced from China? Could this product have been made with a magnet that was not rare-earth, or something other than neodymium?

Industrial workplaces are governed by OSHA rules, but this isn’t to say that rules are always followed. While injuries happen on production floors for a variety of reasons, of the top 10 OSHA rules that are most often ignored in industrial settings, two directly involve machine design: lockout/tagout procedures (LO/TO) and machine guarding.

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